As long as the outflow isn't knocking your fish into the glass LOL the more filtering the better. Shouldn't slow things down too measurably if you use the extension tube, as long as you don't put any bends in it. I have one on my 55g and I lurve it.

I have the 280 and it's a great filter. I know some folks aren't big on Bio-Wheels, but it really works. Also the Emperor have a media compartment which is really handy. I think the 280 is good for tanks up to 45gal. If you are going to get a power filter then I would definitly reccommend either the Emperor 280 or 400.

The extension tube won't slow your filter down any. The flow on the Emperors is adjustable anyway so you can set it anywhere you want it. You'll like the 400...it's a great filter and will give you years of service.

__________________
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Logan J

It will slow it down if it has to draw water over the water line for any amount of distance. But like most people our water levels are to the top where the filter hangs over. Just thought I would add that I was thinking of setting up a half water half soil tank and use the emperor to make a waterfall type thing down some homade rock.

So, once I get the Emperor 400, how long should it run on my existing tank before I can remove the existing filter (in other words - since my tank is all cycled now with bacteria and what-not - how long till the bio-wheel is active and working?)